How to Install Oracle Java 8 (JDK8 and JRE8) In Ubuntu 14.04, 13.10, 12.10, 12.04 and 10.04 Via PPA or Linux Mint How to Install Oracle Java 8 In Ubuntu 14.04, 13.10, 12.10, 12.04 and 10.04 Via PPA You can install Oracle Java 8 (JDK8 and JRE8) In Ubuntu 14.04, 13.10, 12.10, 12.04 and 10.04 Via PPA or Linux Mint machine easily Add the webupd8team PPA repository and install Oracle Java 7/8 using the following commands:

install Oracle Java 7

    sudo add-apt-repository ppa:webupd8team/java
    sudo apt-get update
    sudo apt-get install oracle-java7-installer 

install Oracle Java8

    sudo add-apt-repository ppa:webupd8team/java
    sudo apt-get update
    sudo apt-get install oracle-java8-installer 

Check your installation with this command

    java -version

or

    javac -version

Switching between Oracle Java 7 and Oracle Java 8

Switch to Oracle Java 8 (from Oracle java 7)

    sudo update-java-alternatives -s java-8-oracle

switch to Oracle Java 8 (from Oracle java 7)

    sudo update-java-alternatives -s java-7-oracle

should be under “sudo”

cpan App::cpanminus

cpanm Switch

Source http://www.webupd8.org/2012/09/install-oracle-java-8-in-ubuntu-via-ppa.html

It has touchpad compatible problem

To solve touchpad problem : TouchPad problem in Ubuntu

* Do not install nVidia graphic driver.
* In preference : display scale : 2.0
* Install unity-tweak
* Install dark theme.

* In dark themed ubuntu, default theme of geany attacks your eyes.
So you need to change geany theme to dark.

(1) download any dark theme for geany. ex) at here : Geany theme
(2) see description how to set theme : Repository